Control apparatus



April 25, 1950 Filed April 7, 1945 R. R. STEVENS CONTROL APPARATUS 4 Sheets-Sheet l INVENTOR. Roy 18. Stevens ATYUPNEY R. R. STEVENS CONTROL APPARATUS April 25, 1950 4 Sheet-Sheet 3 a E u @A Q 02 7 m3 mm o$ w: A? u 02 @2 @7m: 01:19amm 5 W H I p PH F April 25, 1950 R. R. STEVENS 2,505,260

CONTROL APPARATUS Filed April 7. 1945 4 Sheets-Sheet 4 50 45 fig. 15

IN VEN TOR.

Roy 19. Stevens BY V I M5 ATTORAEY i atent ed Apr. 25 1950 r UNITED STATES FATENT OFFICE CONTROL APPARATUS Roy R. Stevens, Forest Hills, .Pa., .assignor to 'lhe Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Pennsylvania Application April 7, 1945, Serial N 0. 587,165

said pipes or rods will be lifted out of the well.

Power means such as an engine is provided for turning the drum through the medium of high or low speed driving units adapted to be selectively connected to the engine by individual clutches.

One object of the invention is the provision-of an operators control apparatus for selectively controlling devices, such as the clutches just mentioned, and for also controlling the speed of the power means or driving engine.

On well servicing units of the above type it is desirable to be able to selectively engage either clutch to any desired degree up to full engagement. It is also desirable at times to fully engage one clutch and to at the same time be able to-partially engage the other clutch to provide a jerkto break loose or to start lifting a pipe or rod which it is desired to lift. Further, it is desirable to be able to disengage either clutch Without disengaging the other, or to disengage both clutches at the same time. Still further, it is desirable to operate the engine at any speed, regardless of the condition of the clutches, and it is particularly desirable to be'able to accelerate the engine to any desired degree with either clutch partially or fully engaged, as well as during the act of affecting such engagement.

Another object of the invention is therefore the provision of an operators control apparatus embodying a single control lever and mechanism controlled by said lever in such a manner as to provide for obtaining the selective'control of a lurality of devices or operations, such as of the two clutches and speed of a power means, as above described. l Other objects and advantages will be apparent from the following more detailed description of the invention.

In the accompanying drawings: Fig. 1 is a diagrammatic sectional view of a portion of a well servicing unit embodying the invention; Fig. 2 is across sectional view of one oftwolike clutches shown in elevation in Fig.1; Figs. 3 to 7 are sectional views taken ,on lines 3-3, 4-4, 5-5, 6- B and l-1, respectively, in Fig. 1;- Fig. 8 is a longitudinal sectional view of a valve device shown in Fig; 1 inside elevation; Figs9 and 10 are diagrammatic views-similar to a portion of Flig". 1

but embodying modifications 'of'the' invention;

14 Claims. (01. fez-.098).

Figs. 11, 13 and 14are views similar to Figs. 9 and.

' Description Figs. 1 to 8 As shown in the drawing the reference numeral l indicates a rotatable drum adapted upon rotation to wind up alifting cable 2 forlifting a pipe, rod or the like from a well. On one end of this drum-is mounted a gear 3 while on the opposite end is a larger gear 4; The gears 3 and 6 mesh respectively with gears 5 and 6 secured to turn with coaxially aligned shafts 1 and 8. Each set of gears 5, 3 and 6, 4 forms a reduction gearing, the former constituting a high speed drive connection between shaft 1 and drum l with respect to the drive connection between shaft 8 and drum I, which may be termed a low speed drive connection.

Individual clutches 23 and 24 are provided for selectively connecting the shafts l and 8, respectively, to an intermediate shaft 9 which is operatively' connected through the medium of bevel gearing H] to a drive shaft II. The drive shaft l l is arranged to be driven by a power means in the form of an engine l2.

It will be apparent that when the engine [.2 is operating the engagement of clutch 24 will connect said enginethrough the gears 6 and 4 to the drum I to provide. a maximum degree of lifting power on the cable 2, and therefore a minimum rate of lifting speed for starting and lifting a pipe or rod from the well. With the engine [2 thus connected-tothe drurnl, a partial engagement of clutch 23,will,provide,an additional connection between the engine I2 and drum l to create a jerk on saiddrumand thereby on the lifting cable in orderto break a pipe or rod loose in the well to initiate a lifting operation.

Engagement of clutch 23 when the clutch 24 is disengaged will transmit less power from the engine !2 to the lifting cable 2 but will provid for a higher rateof speed of lifting than provided through the gears 6 and 4, a will be apparent. Moreover when the clutch'23 i engaged a partial engagementfof clutch 24 at the same time' will provide a jerk on the cable 2"to initiate a lifting operation, as will be apparent. The speed at which the cable 2 is wound up on the drum 1 will also vary according to the speed at which engine l2 is operate'dlas will-be obvious. i

The speed'o'f engine lz may be controlled by they are shown in the drawing, for supplying fuel at a rate to provide for operation of the engine at a desired low or idling speed. The'leyera M and shaft !3 may be adjustable out of idling position in a clockwise direction as ;viewed;i

the drawing, for increasing the supply; off 1; to the engine to thereby obtain an engine speed or power output proportional itoi the ldegreeiofg such movement. The maximum speed or output.

of po er of engine I2 may be obtained with the lever I 4 in a position indicated by the dot and dash line l5.

The free endof*leverr i4 isoperatively-connected to one end of a rodlfi the opposite end of which. is .connectedjto a piston H of-ia sp justingdevice it; in a cylinder and-is subiecton-one; face'to pressure of fluid in a pressure chamber I85 A-tthe opposite side ofpistonl I is a non pressure chamber 23 t rough which the rod l6 extends and which contains a; spring 2-l acting-on-piston-= H in opposition to pressurecifiuid in chamber l9.

Chamber !9 is'connected tea speed control pipe 22 throu h which fluid under pressure is adaptedto be supplied to and released" fromsaid chamber hv means-to be hereinafter described.

The pressure ofs ring Zl-against piston ilissuch as to' hold said piston-against movement out of the position in which it is--sh-own in the drawin when t e pressure-ofqfiuid'in chamber l9 is'below a certain degree such= as-10 pounds. When the pressure of fluid in chamber 19 is increased a ovethe chosen degree of 10 pounds s ing 2! will vield to nermit movement of piston I7, in o osition to the pressure of said'spring, to aposition determined-by the pressure of-fluid; in: chamberls, to therebycorresnondingly position-thefuel control'lever f4; When fluid at'a maximumdegree of pres ure is provided in chamher t the piston I! will; move the lever 1.4" to the maximum engine .speed position indicated by the dotand dashline I51 It willthusbeapnarent that-when t e pressure of fluid in chamber 19 does not exceed'thechosen degree of 10-p0unds,

the engine [2" will operate atan idling s eed;

while upon; an increase in such pressure. above said. chosen degree the. speed' of the engine will be correspondingly increased.

The w 1 hes23 and. are d ntica 7. constructionandi operation and are of the type requirin f r e, to e t? n a e e t ndwhkh wh n n y. p i lly nsa ed wil 'become 1 .6 1?- gaged upon dissipation of? such p forc,e,,.but which when. fully en aged willremain engaged. upon dissipationof. such force and will require. force toeiiect disengagement. ljhe essential'ele'ments of such a clutch areshown-by way ofillustration onlrli i is- 2 of he. rawin s ich, sa ect cna view, of clutch; Z3, V

As-.-shown in Fig. Z -of the,dim-wing; the,clutch 2.31 may. comprises; driving; memben 25 secured to the driving shaft.Qin anysuitablem-annen as by-means of a;set; screw;26 to turn with the shaft and. urth r; m i es a: r n-member 5e:

' cured by means of; a; etisce w 28 to-the adjacent enact shaftz p sma ma-sha ts. ihe driv member 21 comprises an integrally formed disc The piston H is contained 29 upon which is splined a coaxlally arranged disc 39. interposed between the two discs 29 and 30 is a disc 3: carried by and having a splined connection. internally with a rim 32 projecting from the driving member 25 over the outer peripheral surfaces of discs 29 and 30. On each of the adjacent' faces of discs 2 9,a 3B, and 3! there is secured a, disc 3la of any conventionalclutch facing material.

It will be seen that movement of the disc 30 in th$gdlll83tl0ll of the disc 29 will squeeze the disc 3! between the two discs 30 and 29 and thereby create a; frictional; driving connection between the shafts-fl a'nd l, while upon relief of pressure of disc 38' on the discs 3i and 29 this driving connection will; bfigbllQkEIl. By suitable adjustment of thepressure of disc 3!] against discs 3| and 29 any desiredpartial degree of engagement, or full engagement, of the clutch can be obtained as will be-apparent'.

For moving the several discs 3fl, 3 l and-29 into engagement a sleeve Mis: slidablymounted on-.

shaft'i and on theend adjacent the disc. 3!! said sleeve isprcvidedwitha taperedactuating sur-..

facets; A plurality ofbellcranks 36:.are spaced:

around the shaft l; although only: one of these bell cranks is-seen in the section shown in Fig. 2;

Each ofthesa bell cranks inlfulcrumedat its.-.

knee on apin al andhasone.endiinscontact with the adjacent s rface of disc 3B. In the-other end" ofbell cranizis mounted'a roller BS-arranged for contact with surface 35' onthesleeve 34.

Movement of sleeve- 34 inthe direction 0f"-the. friction disc lid-onshaft 'l will'iactuatethe bell* rolierfii on t e sleeve-operatingsurface 34. By. properly pos tioningthe sleeve- 34 any desired degree-of clutch-engagementcanbe obtained up to full engagement under which condition the.

roll r willhaveleft the surface- 35 and will be positionedonacylindrical surface 35a-of sleeve. 33 Unon fullengagrement of the clutch the shaft 1 will be secured to turnin unison -with theshaft 9 but with- QIlVflBSS degreeof engagement the shaft-9 may turnat' a faster rate than; shaft 1 a-s--will be a parent.-

A- lever- 39 f ulcrumed intermediate its ends on a pin 49 has a b ffurcated end connectedto pins 4! provided on opposite sides of-a ring-t2 which is journaled in an annular groove in the sleeve 34. The oppositeend of lever 39; is connected by a link- 43*to one endof a rod 44 of-a clutch control; motor 45. The motor 45 comprises a casing -containing a piston dfiwhich is connected o v toms. dsor tion- 5 a mber 41 connected to a clutch engaging pipe 48 w le at he. opp site. s e s am l amh rfifi. on.- nected' to a clutch disengaging pipe 55 Upon supply of, fl id. un er. p es u e o. nip? and therebyto pressurechamber 4 9 ,when pipe 48 is vented, the piston it" will move tothe position in which .it. is shown, in ,thedrawing for thereby ope t n he sve o; awfl heh lut h con..- trolling. sleevelail to. the .;po sition shown in Big. 2,, for diseases ns h lut h, .3. U on. up ly of. fluid under pressure to, pipe; 48, when ..fluid under pressure is released from. pipe 59,. and cha rmen-49, the pressure. of fluid. efiective in chamber will move thepiston 46in thedirecion otthe op p aen f tsi ndslt o,th by ii-l dire tions he: lut iscs 9.; fis fi engagement of the clutch. The degree of eng'a'gement of clutch 23 may be varied according to the pressure of fluid provided through pipe.

48 in pressure chamber 41, while full engagement will be obtained upon providing sufficient pressure in said chamber to move said piston into contact with the end of its cylinder oppcsite the end in which it is shown in the draw-v Sleeve 34 in the clutch 24 is operatively connected by a lever 5! and a link 52 to a rod 53 projecting from a clutch control motor 54, which is identical to motor 45. Themotor 54 therefore comprises a casing containing a piston 55 connected to the rod 53. At one side of piston 55 is a pressure chamber 56 which is connected toa clutch engaging pipe 51 while at the opposite side is a pressure chamber 58 which is connected to the clutch disengaging pipe 50. Upon supply of fluid under pressure to pipe 50, when fluid under pressure is released. from pipe 51, the piston 55 will move to the position in which it is shown in the drawing for effecting disengagement of clutch 24, while upon supply of fluid under pressure through pipe 51 to chamber 56, when fluid under pressure is released from chamber 58 by way of pipe 50, the piston 55 will operate to engage the clutch 24. It will thus'be seen that the control of the two clutches 23 and 24 is identical, a force being required to engage the clutches and to also disengage the clutches, in case they are fully engaged. It is desired topoint out that with the clutches fully engaged, the engaging force, that is, the pressure of fluid in either pressure chamber 41 or 56, may be released without obtaining disengagement of the clutch due to the face that the rollers 38 will be disposed on the cylindrical portion 35a of the clutch control sleeve 33. With either clutch only partially engaged, however, under which condition the roller 38 will be disposed on the inclned surface 35, the clutch will automatically disengage upon release of the engaging force, that is to say upon the release .of fluid under pressure from either chamber 41 or 56 as the case may be.

The structure so far described is employed merely for illustrating one use of the invention and a further description and more detailed showing of said structtre is therefore not deemed essential in the present application. V

The invention comprises operators control means for selectively controlling the supply and release of fluid under pressure to and from the speed control pipe 22, and the clutch control pipes 48, 5'! and 5G and said control means will now be described.

The operators control means comprises a stand which may be in the form of a cabinet having a top wall 60 and a back wall 5|. The top wall 60 is provided with an upstanding boss 52 through which there is provided a bore, and journaled in this bore and extending into the interior of the cabinet is a rotatable control shaft 63; The shaft 63 has an annular collar 64 resting on the upper end of the boss 52 for supporting the shaft 63, and extending upwardly from said collar are two parallel arranged arms 65 having in their ends aligned bores in which is journaled an operating shaft 55. An operators lever 68 has one end disposed between the two arms 65 and is provided with a bore through which the shaft as extends. The shaft 5 and lever 68 may be connected together bya key .59 so that upon vertical movement of said lever,

in the two arms 65 without turning the shaft 63. It will be apparent that through the medium of the two arms 65 and shaft 65, the operators control lever 68 is operative to turn the control shaft 63 in the boss 62.

Mounted on the back wall 6| of the cabinet underneath the top wall 68 are two clutch selector valve devices 'H and 12 which are disposed at opposite sides of a cam 13 mounted on the control shaft 63 for rotation therewith. Below the clutch selector valve device H a clutch control valve device 14 is mounted on the back wall 50 at one side of a cam 15 which is also mounted on the control shaft 63 for rotation therewith.

The clutch selector valve devices it and 12 are identical in construction and each comprises, as shown in Fig. 5 of the drawings, a fluid under pressure supply valve 16 contained in a chamber 11 and arranged to control flow of fluid under pressure from said chamber to a chamber 78. A spring 19 in chamber "ll acts on the supply valve 16 for urging it to its closed position in which it is shown in the drawing. Chamber 18 contains a release valve which is arranged to seat in the same direction as the supply valve 15.

The supply valve 16 has a stem 16a extending into chamber 18 and engagin the release valve 80. Release valve has a fluted stem 8! mounted to slide in a bore 82 provided in a sleeve 83, and extending from said bore into a chamber 84 in said sleeve. Chamber 64 is open to atmosphere through a port 85 and contains a spring 86 acting on a follower 87 which is in contact with the release valve stem 8!, this spring being under pressure and therefore eifective to urge the release valve 8! out of seating engagement with the end of sleeve 83. The sleeve 83 is mounted to slide in a bore provided through a nut 88 which is secured in the casing of the device by screwthreaded engagement. The sleeve 83 has an annular groove in which there is disposed a sealing ring 89 havin sealing and sliding contact with the wall of the bore through nut 88 to prevent leakage of fluid under pressure from chamber 18 along the outer surface of said sleeve. The outer end of chamber 84 in sleeve 83 is closed by a cap 9|] the outer end surface of which is rounded for contact with the peripheral surface of cam 13, it being noted that the two caps 99 of the w selector valv'e devices ll and i2 engage diametrically opposite portions of said cam.

The supply valve chamber 11 in both of the selector valve devices (I and 12 is connected to a fluid pressure supply pipe 9! leading to the clutch control valve device 14. The release valve chamber (8 in the selector valve device H is connected to the clutch engaging pipe 48, while in the selector valve device 12 the corresponding chamber 78 is connected to the clutch engaging pipe 51.

The cam 13 is so deigned that with the operators control lever 68 and cam E3 in a neutral position as shown in Figs. 1 and 3 and 5 of the drawings, the fluid pressure supply valves 16 in the two selector valve devices will be seated by their respective springs 13 whie the sleeves 83 will be moved out of contact with the release imosphere. The cam '53 is provided with a shoul- ;der or rise 92 which upon rotation of the operators control lever 58 in a counterclockwise direction, as viewed in the drawing, will efiect movement of sleeve 83 in the selector valve device atrno's'e'hefre through a breather port I136.

111','i11t0 contact with then actuate said valve to unseat the supply-valve I6 :so as. to thereby close communication between chamber I8 and atmosphere by way of port I35v and open said chamber to chamber I1 so that. fluid under pressure may flow from the supply pipe SI to the clutch engaging pipe 48. When the selector valve devicelI is thus operated, the

7 parts of the selector valvedevice 12 will remain in the position in which they are shown in Fig.

of the drawings as will be apparent.

and the clutch engaging pipe 57, the parts of the.

selector valve device iI remaining in the position in which they are shown in Fig. 5 of the drawings during such operation. Return of the operators control lever $3 to its neutral position fromeither direction of rotation out of its neutral position will effect operation of the selector valve device.

II or 7.2 to open the respected clutch engaging pipe A8 or -57 to atmosphere.

It will thus be seen that the operator by moving his control lever 68 from neutral position in a generallv horizontal plane in one direction may supply fluid under pressure tothe clutch engaging pipe48 while retaining the clutch engaging pipe 5.! open to atmo phere, or upon movement in the opposite direction may supply fluid under pressure to the clutch en aging pipe 51 while retaining pipe 48 open to atmosphere. 7

The supply of fluid under pressure to pipe 9| for supely to either one of the clutch engaging pipes 38 or El is arranged to be controlled by the clutch control valve device It.

The clutch control valve device I4 as shown in detail in 'Fig. 7 comprises a casing containing two spaced coaxially aligned flexible diaphragms Illi) and I HI. These diaphragm are of the same area and at their centers are connected together for movement in unison by a rigid connecting structure Hi2. Between the two diaphragms lllllancl IBI is a chamber H33 connected to a pipe 04 which is arranged to be constantly sucpied with fluid under pressure from any suitable source. At the op osite face of diaphragm i Elli is a chamber its which is in constant communication with At the Upposite iace o diaphragm Ill-I i a control chamber Ell? which is connected througha stabilizing choke 128 to a chamber 39. The chamber I09 is connected to pipe 9; leading to'the supply valve chamber ii in the two clutch selectorvalve devices H and I2. 7 A coil re ulating spring I IE! contained in chamber 593 and encircling the structure I02 bears at the release valve-'80. andone end on a ledge III of the casing, while the normal'position the spring l H! is fully expanded.

A port H3 through the ledge Ill provides for equalization of the pressure of fluid at opposite sides of said ledgawhereby'the adjacentfaces-of tl' !'etwo diapliragms I00 and :IDI will be con- 'fstantly :subj ected to the .same .pressureof .fiuid.

- The connecting structure IllZ-adiacent the diaphragm. IOI has a chamber II4 open through ports II5 to chamber I93 and containing a fluid pressure supply valve H6 and a spring III acting on said valve for urging it to a closed position in which it is shown in the drawings. The supply valve I I6 hasa fluted stem I I8 extending through a bore in the connecting structure 502 into a chamber II9 which is open through one or more ports I20 to chamber I09. Chamber H9 contains a release valve IZI arranged to seat in the same direction as the supply valve H6 and engaging the stem I I8 of said supply valve. The release valve IZI has a stem I22 disposed to slide in a bore provided axially in a plunger I24 which is slidably mounted in asleeve I25 secured in the casing. The release valve stem I22 projects into a chamber I 26 formed within the plunger I24 and therein engages one side of a follower I2I. A spring I28 in chamber I25 engages the opposite side of follower I21. This spring is under pressure and therefore constantly effective to urge the sleeve 124 in a direction away from and thus out of seating engagement with the release valve I 21.

Chamber I26 is in constant communication with atmosphere through one or more ports I29 in plunger I24 and one or more registering ports I 30 in sleeve I25. The plunger I24 is provided with an annular groove in which there is disposed a sealing ring I'3I having sealing and rolling contact with the bottom wall of said groove and the adjacent surface of sleeve I25 for preventing leakage of fluid under pressure from chamber I I9 past said plunger to atmosphere.

Beyond the outer end of sleeve I25 an annular spring seat I32 is secured to the plunger I24, and interposed between this spring seat and the portion of the casing encirc ing the sleeve I25 is a coil bias spring I33 which is under a chosen degree of pressure and therefore constantly effective to urge said plunger in a direction out of seating engagement with the release valve I2I.

The outer end of chamber I26 in the plunger I24 is closed by a follower 534 having screwthreaded engagement with said plunger. A look nut I35 on the follower I34 is provided to engage the outer end of plunger !24 for securing said follower in an adjus ed condition. The outer end of the folower I34 is arranged for contact with the peripheral surface of cam 75.

Projecting into chamber I85 and having screwthreaded engagement with the casing is a lim ting screw I35 arranged for contact with the adjacent end of the diaphragm connecting structure I02 for limiting movement of said structure in the direction of the left hand. A look nut I3'Ia provided on the screw I35 is arranged for contact with the casing to lock said screw in an adjusted position.

The. cam I5 is provided with a recess I3! which, with the operator's control ever 58 in neutral position in its horizontal plane of movement, is adapted to receive the end of the follower I34 under the action of spring !33. With the follower I 34 and plunger I 24 thus positioned, the

,parts of the control valve device will assume the position in which they are shown in Fig. 7 of the drawings, in Whichposition the release valve IZ-I is opened underpressure of spring I28, the supply valve H6 is closed under pressure of spring Ill, and spring H0 is fully expanded. With the re lease valve..l2I .thus open the supply pipe 9!, con nected tothe two selector valve devices I I audit, will 'be open to atmosphere through chamber I26 .9 in the plunger I24 and thence through ports I29 and I30.

As above mentioned, the cam.I is shown in Fig. '7 in a position it assumes with the operators control lever 68 in neutral position in the generally horizontal plane of movement, in which position said lever is shown in Figs. 1 and 3 of drawings. At one side of this neutral position the lever 68 has a zone of movement I38 (Fig. 3) for graduating the degree of partial engagement of clutch 24, and beyond this zone the lever 68 has a position I39 to effect full engagement of clutch 24. At the opposite side of neutral position. the lever 68 has a reverse y arranged zone I40 for providing different degrees of engagement of clutch 23 and beyond this zone a position I4I for efiecting full engagement of clutch 23 as will hereinafter be described in greater detail.

The control shaft 63 is provided in one side with anarcuate slot I42 (Fig. 3) into which extends the end of a screw I43 secured in the boss 62 extending upwardly from the top wall 60 of the cabinet. The end of this screw is adapted to engage with the opposite endsof slot I42 for limiting movement of the operators control lever 68 in a generally horizontal plane, and the length of said slot is such as to prevent movement of said lever past either of the positions I39 or I4I,,but providing for adjustment of said lever between said positions. 7

At one side of recess I31 the cam has a peripheral surface I44 adapted upon clockwise movement of lever 08 out of its neutral position to effect displacement of follower I 34 toward the left hand (Fig. '7) a degree which is proportional to the extent of such movement. A maximum degree of displacement of follower I34 will be obtained with the lever in the position I39, while the degree of such displacement obtained with said lever at the adjacent end of zone I 38 will equal the space shown in Fig. '7 between the adjacent ends of the diaphragm connectingstructure I02 and of the limiting screw I36. At the opposite side of recess I 31 the cam I5 has a surface I45 which is identical to but arranged reversely of the surface I 44 for effecting displacement of I follow'er I34 out of its normal position upon counterclockwise movement of lever 68 from neutral position toward the position I4I. In the position I4I the same maximum degree of displacement of follower I34 will be obtained as in the position I39. while at the adjacent end of zone I 40 the displacement of fo lower I34 out of its normal position will be the same as obtained at the opposite end of the zone I38. I I

The operation of the clutch control valve device I4 is as follows: 4'

With the operators control lever 68 in neutral position permitting follower I34 to. enter recess I31 in the cam I5, the release va1veI2I is opened .50 as to connect the pipe 0| to atmosphere as above described. An initial relatively small degree of movement of lever 68 in either direction out of neutral position is adapted to efiect operation of cam l5 to displace follower I34 in the direction of the left hand (Fig. '7) against the opposing pressure of spring I33 to a degree sufficient for movin plunger I24 into seating engagement with the release valve I2I and, ifdesired, for then actuating said release valve to unseatfto a slight degree the fluid pressure supply valve H0 from its seat on the diaphragm lever 58 is moved from neutral position to some l0 position. within the zone I38 in order to effect displacement of follower I34 and thereby of the supply valve I IS in the direction of the left hand (Fig. 7) to a position correspondin to that of said lever. With the supply valve II 6 thus opened fluid under pressure will flow from cham-.- ber I03 between the two diaphragms I00 and NI past said valve to chamber H9 and thence 'to chamber I09 and pipe 9|. As fluid under pressure is thus supplied to pipe 9| it will also flow from chamber I09 through choke I08 to chamber I0? and therein act on the diaphragm IOI in opposition to spring I I0.

When the pressure of fluid thus obtained in chamber I0? is increased to a degree sufficient to overcome spring H0, the diaphragm IOI will defiect against said spring relative to the supply valve H3 which will be held against movement due to the expansive force of spring III. Fluid under pressure will however, continue to flow to pipe 9| and thus to chamber I01 until the diaphragm I0! deflects the diaphragm connecting structure I02 into seating engagement with supply valve II6 which will then prevent further flow of fluid under pressure to said pipe. The pressure of fluid obtained in pipe 9I will therefore be limited to a degree corresponding to the displacement of the supply valve II6 from its normal position in which it is shown in Fig. '7 and hence corresponding to the position of lever 68in zone I38.

If the operator now desires to increase the pressure of fluid in pipe 9I he will move the lever 68 in a clockwise direction (Fig. 3) further into the zone I38 and this movement will again open the supply valve H6. Fluid under pressure will then flow past the supply valve II6 to pipe 9I and at the same time through choke I08 to diaphragm chamber I0! and, as the pressure of fluid in said chamber increases, the diaphragm I M will be deflected further against spring H0 and finally move the diaphragm connecting struc ture I02 into seating engagement with the supply valve I'I6 when the pressure of fluid in said pipe is increased to a degree corresponding to the position of said valve and therefore the position of the operators control lever 68 in zone I30.

If the operator moves the control lever 68 to the end of zone I38 adjacent position I39 the supply valve II3 will be so positioned as to be engaged by the diaphragm structure I02 in a position of suchstructure in which it will substantially engage the adjusting screw I36. Thus in this position of lever 88 a maximum degree of regulated pressure will be obtained in pipe 9|. If the lever 38 is moved to the position I39 to effect further unseating of the supply valve II6 the pressure of fluid from pipe I04 will equalize into pipe 9i, since the adjusting screw I30 will prevent movement of the diaphragm connecting structure I02 such as required to close the sup plunger I24 will move said plunger in the dijrection'of cam l5 as permitted by the cam surface I44 and, as a result,said plunger will move out of contact with the release valve IZI since spring I28 will hold saidvalve against movemerit with said plunger. Fluid under pressure 11 will then be released from pipe 9| past the re-.@ lease valve I2I and thence to atmosphere, and at the same time the pressure of fluid in diaphragm chamber It? will correspondingly reduce. As the pressure in chamber IITI is thus reduced, spring II!) will move the diaphragms and their connecting structure I02 and thus the seated supply H6 and the release valve I2I in the direction of the plunger I24 and finallyseat the release valve against the end of said plunger, when the pressure'of fluid in chamber I01 and pipe becomes reduced to a degree corresponding to the new position of the operators control lever. Another adjustment of the operators control lever in the direction of neutral position, but 'still'in the control zone I38, will efiect another and corresponding reduction in the'pressure of fluid in pipe SI, as will be readily apparent. If the operators control lever is returned to the neutral position the plunger I24 will be so con-.

ditioned by spring I33 that the release valve I2] will remain open upon complete release of fluid under pressure from pipe el and chamber I01, as will be readily apparent from the above description.

It will now be seen that the operator by adjustment of lever 68 out of neutral position in a clockwise direction, as viewed in Fig. 3, may cause the clutch control valve device I4 to provide any doe sired degree of pressure in pipe 9I between atmospheric pressure, obtained in the neutral posi- :tion of said lever, and a maximum degree of pressure obtained in the position I39 of said lever.

if the operators control lever 68 is moved in a counterclockwise direction from its neutral position either into zone I or to position I4I, as viewed in Fig. 3, the clutch control valve device I4 will be operated by the cam surface I to provide the same difierent pressures of fluid in pipe 9| as provided in corresponding positions of said lever in zone I38 or in position E39 aswill be readily apparent.

It will now be seen that if the operator moves thecontrol lever 68 out of neutral position in a counterclockwise direction, as viewed in Fig. 3, the selector valve device II will be operated to connect the clutch control pipe 48 to pipe SI and the clutch control valve device I4 will be operated to supply fluid through said pipes to the clutch control motor 45 at a pressure determined by the position of said lever for thereby actuate ing said motor to engage clutch 23. The clutch grimy be thus engaged to any degree less than full engagement by proper adjustment of lever Iii}v in the control zone I40, and if said lever is moved from said zone back to its neutral position the consequent release of fluid under pressure from the clutch control motor 45 to atmosphere by way of pipe 48 and through the selector valve device TI will permit disengagement of clutch '23. However if the lever 58 is moved to the position I4I a maximum pressure of fluid will be provided by the clutch control valve device i4 through pipe 48 to the clutch control motor 45 to thereby effect full engagement of clutch 23. If the clutch 23 is thus fully engaged it will then remain engaged when the operators control lever 68 is moved back to neutral position for effecting a complete release of fluid under pressure from the clutch control motor 45 by Way of pipe 48 and theselector valve device II. V j a When the operators lever 58 is operated as'j ust described pipe 51 leading to the clutch control 12 motor 54 will be maintained open to atmosphere through the selector valve device 12 so that clutch 25 will remain disengaged. However, if the operator moves his lever in a clockwise direction as viewed in Fig. 3, into the zone I38 he will effect operation of the selector valve device 12 to establish communication between the clutch control pipe 57 and pipe 9I so as to thereby supply fluid under pressure from the clutch control valve device I4 to the clutch control motor 54 to effect engagement of clutch 2d. The degree of engagement of clutch 24 may be varied according to the position of the operators lever 68 in zone I38 and if only partially engaged the clutch may be disengaged upon movement of said lever out of said zone back to the neutral position. However, movement of lever 68 to position I39 will effect full engagement of clutch 24, as a result of which, said clutch will remain engaged upon complete release of fluid under pressure from pipe 51. When the lever 68 is operated as just described to effect engagement of the clutch 24 the selector valve device TI remains in the condition opening pipe 41 from the clutch control motor 46 to atmosphere.

A clutch release valve device I58 is provided for supplying fluid under pressure to pipe 50 and thereby to the two clutch control motors 45 and 54 for effecting disengagement oi the clutches 23 and 24 after said clutches have been fully engaged.

As shown in Fig. 8, the clutch release valve device- I comprises a casing having a chamber i5I open to pipe 50 and containing two oppositely seating poppet valves I52 and I53. The valve I52 has a fluted stein I54 extending through a bore provided in a wall which separates chamber IS I from a chamber I55. Chamber I55 is connected through an air cleaner I56 to a passage I57 leading to the fluid pressure supply pipe I04. A spring I58 in chamber I55 acts on the valve stem I54 for unseating the valve I 52 and for seating the val ve I53. The valve [53 has a fluted stem I55 extending through a bore in a wall which separates chamber I5I from a chamber I60 which is open to atmosphere through a passage IEiI. The casing further contains a piston I52 having an. operating stern I63, extending into chamber H55 in coaxial relation with the valve stem I59. At one side of piston I62 is a pressure chamber 4 h ch is pen t a pas age 4 5 onnec to the speed control pipe 2'2. At the opposite side of i t I62 is a hamb r I h o whic the piston stem I53 extends and which is open to atmosphere through passage I6I. A control spring I61 contained in chamber I66 and encircling the piston stem IE3 is supported at one end on the casing while the opposite end bears against piston I62.

The pressure of spring I6? against piston I62 is such as to require fluid at a pressure such as 10. pounds in chamber I64. to move the piston against the opposing force thereof. The piston I62 when it is thus moved is adapted to act through. stem I63, which will move into contact with the valve stem I59, to open the valve I5 and o los the valve 5 for h reby p ing the clutch release, pipe 50 to atmosphere by way of passage IEI. When the pressure of fluid in chamber I54 is less, than 10 pounds, spring I61 will maintain piston I62 in the position in which it is shown in the drawing so. that spring I58 will, open. valve I52 and, close valve I53 to thereby Supply fluid under pressure from pipe I 04 to pipe 50 for operating the clutch control motors'45 and/or 54 to effect disengagement oi the respective clutches 23 and 24.

Secured to the back wall SI of the control cabinet directly under the lower end of the operating shaft 63 is a speed control valve device I which is identical in construction and in operation to the clutch control valve device 14, with the exception, that it does not include a limiting screw, such as I36 associated with the clutch control valve device 14. It is therefore sufficient to point out that the speed control valve device I10 comprises a follower I1I corresponding to follower I34 of the clutch control valve device 14, and which is operable upon displacement into the device to vary the pressure of fluid in pipe 22 according to the degree of such displacement, or according to its position with respect to its normal position in which it is shown in Fig. 1 and in which the speed control pipe 22 will be open to atmosphere, whereby any desired pressure may be attained in the speed regulating device I8 to cause a corresponding adjustment in speed of engine I2. 1

For controlling the displacement of follower I1I of the speed control valve device I10 said follower is engaged by one end of a rod I12 which extends through an axial bore provided from end to end through the control shaft 63. The opposite end of rod I12 terminates between the two arms 85 at the. upper end of the control shaft 63 and between such arms operatively engages with the periph eral surface of a cam I13 provided On the operators control handle 68. q

In the most elevated position of the operators control lever 68, in which position said lever is shown in Fig. 4 of the drawings, the cam I 13 permits movement of the rod I12 in an upward direction to permit follower I1I of the speed control valve device I10 to move to its uppermost position for opening speed control pipe 22 to atmosphere. A shoulder I14 on cam I13 engages one side of the rod I12 in this uppermost position of the operators control lever 68 to define said position and to prevent further upward movement of said lever. The cam I13 is so formed that upon downward movement of lever 68 the rod I12 and thereby the plun er I H of the speed cont ol valve device I10 will be moved in the direction of said device in accordance with the extent of such downward movement, the maximum downward movement being obtainedewhen the lever is in the position indicated by the dot and dash line I15 Fig. 4) It will thus be seen that by proper ad ustment of the operators control lever between its normal position and its maximum pressure position indicated by the dot and dash line I15, any desired degree of pressure may be provided in the speed control pipe 22 between atmospheric pressure and a maximum degree.

In a position of control lever 68 indicated by a'dot and dash line I15 the speed control valve device I10 is adapted to be conditioned to provide in pipe 22 a cho en de ree of pressure such as 10 pounds. It will be noted'that this pressure effective in piston chamber I54 of the clutch rebe seen that with the operatorscontrol leverin its normal position, as well as in all positions between normal position and the; position indicated by the dot and dash line I1I iifin 4 of the drawings, the engine l2 will be caused to operate at idling speed, and the clutch release valve device I5fl will be conditioned to supply fluid under pressure to pipe 50 to effect operation of the clutch control motors 45 and 54 to effect disengagement of clutches 23 and 24, while upon adjustment of said lever out of the position indicated by the dot and dash line I16 to any position between said line and the dot and dash line I15, fluid will be supplied to pipe 22 at a pressure which will effect operation of the clutch release valve device I53 to open pipe 58 to atmosphere and at the same time will cause operation of the speed adjusting device I8 to accelerate the engine I2 to a degree corresponding to the position of said lever.

Secured to the back wall SI of the cabinet are two oppositely arranged resistance or centering devices I11 and I18 which are provided for opposing manual movement of the operators control lever 68 in either direction from its neutral position in a generally horizontal plane and which are automatically operative upon release of manual force on said lever to return said lever to its neutral position. These two spring devices are identical, each comprising a casing containing a plunger head I19 subject to pressure of a spring I and having a rod IBI urged by said spring in a direction for engaging a finger I82 projecting from the operating shaft 63. The two rods IBI are of such length as to permit contact between the respective plunger heads I19 and the casing with said rods engaging opposite sides of the shaft centering finger I82 when the contro lever 68 is in neutral position. Movement of lever 68 out of neutral position in a clockwise direction is opposed by spring I80 in the resistance device I18, while upon removal of manual force from said lever said spring will automatically return said lever and the control shaft 63 to their neutral positions. The resistance device I11 is eifective in the same manner in case the operators control lever is moved out of its neutral position in a counter-clockwise direction.

Operation Figs. 1 to 8 In operation, let it be initially assumed that the operators control lever 68 is in its neutral position Figs. 1 and 3 with respect to its horizontal plane of movement, and in its uppermost position (Fig. 4) with respect to its vertical plane of movement. With the lever 68 in its neutral position the selector valve devices H and 12 are both conditioned to open the respective clutch engaging pipes 48 and 51 to atmosphere; the clutch control valve device 14 is conditioned to open pipe 9| to atmosphere; while the speed control valve device is conditioned to open the speed control pipe 22 to atmosphere. With the speed control pipe 22 open to atmosphere, the clutch release valve device I50 is conditioned, as shown in Fig. 8 of the drawngs, to supply fluid under pressure to pipe 553 through which pipe the fluid thus supplied will flow to the clutch control motors 45 and 54 to effect operation thereof to disengage both clutches 23 and 24;

Now let it be assumed that the operator desires to en age c utch 24 to initiate a lifting operat on. and to at the same time maintain clutch disenga ed. To accomplish this he will move his control lever 58 out of its uppermost position shown. in Fig. in a downward direction to at least the position indicated by the dot and dash line H5, or if he so "desires he may move it beyondthis position to thereby effect operation of acetate sure of iiuid thus provided in pipe 2 2 will effect iop'eration of the 'clutchrele'ase valve evice its to open the clutch disengaging pipe 59 to atmosphere 'so as to release fluid under pressure from chambers 49 and 58 in, respectively, the clutch control motors t and 54.

:At the same time as'the operator moves lever *68 downwardly "toat least the position indicated by 'dot and dash line H6, he will also move'it out "of-nedtralposition in a clockwise direction (Fig. 31 110 thereby effect operation of the selector valve device 72 to connect pipe 51 to pipe '9! and to also efiect operation of the clutch control valve "device-1t to supply fluid under pressure through said-pipes to the clutch control motor as to effect operation of said motor to engage clutch 26. Ihe -operator" may thus efiect any desired degree "of partial engagement of clutch 2% or full engagement thereof, depending upon the position to tivliich he 'moves his lever as hereinbefore described.

A't'the same time as the operator moves'the lever -68 to effect engagement of clutch 2 3, or aftersuch engagement has been eiiected, he may adjust the lever'63 downwardly in a vertical di- "rection from the dot and dash line lit, to "a se'lected position to effect operation of the speed control valve device I? to accelerate engine I? "to a desired degree, whereby a lifting operation at a desired speed will be efie'cted 'through the medium of 'c'able 2. In case the clutch it is less than fully engaged and the operator desires to 'eiTect disengagement thereof he may return lever 68 to neutral position for thereby releasing fluid under pressure from pipe 5?, whereupon the clutch 24 willfully disengage. In case the'clutch 2 3 has been fuliy engaged'however, and the operator desires to disengage it, he must return lever'fit-not on'lyto its neutral position'for opening pipe-5'?to atmosphera'but he must also permit movement of said lever in an upward direc-. tion to at least *the positionindicated by the dot and-dash line lit for thereby'reducing the pressure in thespeed control pipe 22 and the clutch release valve device 150 to a degree suificient to permit opening of valve E52 in said device, wheres upon fluid under pressure will-be supplied to pipe -58 for actuating the motor 54 to eiiect disen- ..gagement of clutch 24.

In the same manner as just described, the op- -erator,=by moving his lever 58in a downward direction and in acounterclockwisedirection out of neutral position, may efiect engagement of clutch 2%, either partially or-fully, while retaining clutch 2' 3 disengaged, and-at the same time -he may accelerate engine l-2 to any desired de- -gree for thereby efiecting a lifting operation through the medium of cable '2. Upon return of lever'68 to its neutral position disengagementof clutch =23 will occur in case said clutch is not -fully engaged. In case the clutch 23 has been fully engaged however, the- 0 orator must return lever 68' not only to neutral position but also in a vertical direction to at least the position indicatedby line M6 to thereby effect operation of the clutch release valve device I53 to supply fluid to pipe 55 for operating the clutch control 'motor 45 to disengage clutch 23.

.It'will thus be seen that the operator has selective control over each of the clutches 23' and A 24 and: may selectively effe'ct engagement of 16 either :of said clutches to-any desired degree up to full engagement, and may effect disengagement of said clutches when desired, and may also cause operation of the'engine l2 at any desired speed either after the clutches have been engaged or during the process of engagement,

as desired.

" Nowlet it he assumed that the operator has actuated lever '68 to effect full engagement of clutch 24 and he'desires to at the same time eilect engagement of clutch 23 to provide a jerk on the lifting cable 22. To accomplish this he will move lever (98 from the left hand side of its neutral position to the right hand side, maintaining said lever depressed :to at least the position indicated by the line H6 or any position below said line. This operation of lever 68 will efiect a release of fluid underpressure from pipe but maintaining the lever depressed as ,just mentioned will maintain suificient pressure in pipe 22 to prevent operation of the clutch release :vialve device i to supply fluid under pressure to pipe 59, whereby the clutch control motor 5% willnot be operated, "and the clutch 2d will remain "engaged. Movement of lever 6.8 from the left hand side of its neutral .position'to the right ihand'sid'e as just mentioned will however, effect operation of the selector valve device TI and of the clutch control valvedevice T4 to supply fluid under pressure to the-clutch motor e5 to thereby efiect "operation of said motor to engage the clutch 23. Thus, with the clutch 2% fully engaged, the clutch 23 may be also engaged to provide the desired Jjerk on the'liiting cable '2, and at the same time, by proper adjustment of the lever 68 .in its vertical plane of movement, the engine i2 maybe caused to operate at any selected speed.

When clutch 24 is'fully'engage'd and the operator operates 'lever'iiB' that the same time engage'clutch 23', it'is intended that the degree of engagement of the latter clutch will be limited to only partial engagement, so that returning lever'fifi from the right hand side of neutral positionto neutral position will effect disengagement of'clutch'23, w'hile retaining-clutch 24 engaged. WithFthe latterclutch still engaged the engine may then 'be operated at any desired speedaccording to the vertical position of lever in'order to continue the lifting operation as desired.

When it is desired to discontinue the lifting operation just described the lever "38 need only be returned vertically to its normal position shown in Fig. 4 due to which the clutch release valve device I50 will operate to supply fluid under pressure to pipe'fiilto thereby effect operationof motor-5 5 to disengage clutch Z iyand the speed'of the engine will also reduce to idling, as will be apparent.

On the other hand,if clutch23 is engaged, the operatorby proper manipulation of lever 58, may at the same time cause partial engagement of clutch 24 and subsequent disengagement of said clutch, andialso cause the engine to operate at any selected speed, as will be readily apparent from the above" description.

It will now be'seen that either clutch 23 or '24 may be engaged to any desireddegree while retaining the other disengaged, or both clutches may be engaged at the same time. Either clutch may be disengaged'while the other is disengaged,

"or if'both are engaged at the-same time,'both may be disengaged, according to the will of the operrator. This colitfdl of the clutches-is obtained by movement of lever. 68 merely to one side or the other of neutralposition, or in an upward direction to at leastline [T6 to obtain disengagement of a .fully engaged clutch.

It will .be furthernotedthat acceleration of the engine i2 is controlled'by movement of lever 68 in a downward direction from the line I16 and that the control of engine speed fistherefore separate from clutch control, with one exception, whereby the clutches maybe engaged and disengaged from a partial degree of engagement with the engine operating'atany desired speed. The only exceptionis that, todisengage a fully applied clutch, the-lever 68 must be moved to a position the s ngle control leverfit, the operator may then obtain any desired control of'engine speed and of the clutches necessar'yto provi'dea most difficult operationof the lifting apparatus.

Description Fig. .9

After the operator has moved'tnecontrol lever 68 to either position I 39 or I 41 (Fig. 3) to effect full engagement o'f clutch 14 or clutch 23, respectively, as above described, ltisinten'ded that he will move'or will perm-itimovement "of said lever by either resistance device 111 or l'ltback to its neutral position "forreleasing fluid under pressure from chamber 56 of' the clutch control motor 54 or'from chamber-41 of the clutch con-- trol motor 45 and then by vertical-adjustment of said lever regulate the engine speed for controlling the lifting operation. .Bysmovingilever 68 back to neutral position. as just mentioned he will release fluid under pressure from chamber 4'! or chamber 56,-depending uponwhich clutch is engaged, and thereby relieve the clutch parts 4|, 42, 34, 36 etc. of force, which. is unnecessary with the clutch fully engaged, in order to 'minimize wear of said parts.

With clutch '23 fully engaged andthe pressure of fluid relieved in chamber 41 as just described, if the operator should for any-reason again move lever 68 to position -I-4l he willv again supply fiud under pressure to said chamber but will. accomplish nothing by such operation since the piston 46 is already in itsouterclutch engaging position. Howevensuch. resupply-of fluid under pressure to chamber 41 is undesirable in that it represents a useless waste. of fluid under pressure. This same waste of compressed will also occur if, when clutch 24 is fully engaged the operator should move lever 58. from neutral position back to position i39- as will be apparent.

In addition to. theabove, it willbe noted that whenever the lever 68is operatedto: effect engagement of either clutch, it ismoved downwardly to at least the. position 1.15 (Fig. 4) so as to release fiuid under pressure from the clutch disengaging pipe 58. This release of fluid under pressure from pipe Stand therebyfrom chamber 49 or 5B is essentialinathe respective motor 45 01:.54 whichv isagoing tobeoperated to effect engagement-oi the selected clutchflitjor v2J1, but is unnecessary inthe other motor. as wlillibe readily apparent. Moreover this release of fluid under pressuretrom chamber 48 or 58' in the motorfor the clutch which-will, remain. disengaged is undesirable since when fluid underpressure is sub sequently resupplied to the one of said chambers required to effect disengagement of the engaged clutch, the otherone of said chambers has to be refilled with fluid under pressure In other words, when lever 6B is operated to engage, for instance, clutch 23 and is then operated to subsequently disengage said clutch, a needless release and then resupply of fluid under pressure from and to chamber 58 in the motor for clutch 24 takes place. The same needless release and resupply of fluid under pressure from and to chamber 49 will occur when, with clutch 23 disengaged, clutch 24 is engaged and disengaged. No harm or undesired result in so far as operation of the structure is concerned comes from this needless release and subsequent supply of fluid under. pressure from or to chamber 49 or chamber 58, but it .does cause an unnecessary waste of compressed air.

If it is desired. the waste of compressed air under the conditions above set forth may be avoided by the structure shown in Fig. 9 of the drawings.

According to this modification I associated with the clutch control motor 45 an intercepting valve device 250 which is arranged to control communication between control pipes 48 and 50 and the respective motor chamber-Mand es, while a like valve device 261 is associated with the clutch control motor 54 for controlling communication between the control pipes 51 and 5B and the respective motor chamber 56 and -58.-

Each of the intercepting valve devices 26% and 25-2, may, for illustrative purposes only, comprise a casing 252 having a bore in which. there is slidably mounted a piston like slide valve 263. The slide valve 263 is operatively connected-to one end of a link 264. In the intercepting valve device 26% theopposite end of linl; 264 is operatively cennected to the piston rod link 43 so that the respective slide valve 2E3is movable with and by piston at. In the intercepting valve device 26 i the opposite end of link 26 is-similarly oper atively connected to link 52 for movement wit) and by piston 55 in motor -54. k

The slide valve 263 has two cavities 265 and 266, and the casing 262 has a relatively small port 26'! open to atmosphere and adapted to be connected to cavity 265 when the respective piston 46 or'55 is in its clutch disengaging position, andadapted to be connected to cavity 256 when sa d piston is in its outermost or clutch engaging position.

In motor 45, when piston 46 is in its inner or clutch disengaging position the cavity 266 in the intercepting valve device zsc opens communica tion through pipe 48 to piston chamber 41, while piston chamber 49 is open to cavity 265' and thus to the atmosphere by way of port 261, and pipe 59 is lapped by the respective slide valve 263. The same conditions exist in the intercepting valve device 251 when piston 55 of motor 54 is in its in her or clutch disengaging position. It will be noted that both piston chambers 49' and 58 are: at this time open toatmosphere and disconnected from pipe Stiwhich at this time may be supplied with fluid under pressure;

Now assuming that it is desired to engage clutch 2 3- the operator actuates lever 68 in the same'manner as before described to" 'releasefiuid underpressure from pipe 59 and to Supply fluid underpressure to pipe 48. Fluid under pressure thussupplied to pipe 43 will then flow through cavity 266 in the intercepting valve device 260 to. piston chamber 47 and therein act to move gasses the piston 46 in an upward direction to cause the clutch 23 to engage. The cavity 266 is of such a length as to maintain open the communication between pipe 48 and piston chamber 49 for move ment of piston 46 required to efiect any desired partial degree of engagement of clutch 23 so that if the operator desires to disengage said clutch he may do so merely by releasing fluid under pressure from pipe 48. However, if the operator moves lever 68 to position I4I to effect full engagement of clutch 23, the cavity 266 in slide valve 263 of the intercepting valve device 260 will move out of registry with pipe 48 and into registry with port 261 just before piston 46 attains its uppermost position, the end of pipe 48 being lapped by said slide valve in this position. It will thus be seen that after the piston 46 attains its clutch full engaging position the actuating fluid pressure in chamber 41 will be released to atmosphere which will automatically relieve the clutch parts of the actuating force, and this release is restricted by the small size of port 261 in order to maintain a sufficient pressure in chamber 41 on piston 46, after the supply of fluid under pressure to said chamber is cut oil by slide valve 263, to ensure movement of piston 46 to its uppermost clutch engaging position.

. After the clutch 23 has been engaged, the operator may move his lever back to neutral position, particularly due to the automatic return tendency of centering device I I1, and thereby open pipe 48 to atmosphere. With clutch 23 fully engaged if the operator should then for any reason move lever 68 back into zone I49 or to position MI and cause a resupply of fluid under pressure to pipe 48, the chamber 41 in motor 45 will not be needlessly recharged with fluid under pressure since the communication between said pipe and chamber is closed by the respective slide valve 263. An unnecessary use or waste of fluid under pressure can not therefore result from such unnecessary operation of lever 68.

In the clutch engaging position of piston 46 it will also be noted that chamber 49 will be connected to pipe 59 through cavity 265 in the respective slide valve 263, so that when the operator desires to disengage clutch 23 he may do so by operating lever 68 to supply fluid under pressure to pipe 59 and thence to said chamber. Upon such supply of fluid under pressure to chamber 49, the piston 46 will be moved in the direction of its inner or disengaging position, the cavity 265 in the respective slide valve being of such length as to maintain the supply of fluid under pressure from pipe 59 to chamber 49 until just before said position is attained, at which time said cavity will move out of registry with pipe 59 and into registry with the release port 261. The restricting effect of release port 26! will then maintain suflicient pressure in chamber 49' to ensure movement of the piston 46 to its disengaged position, following which said pressure will be fully dissipated through said port to relieve the clutch parts of force therefrom. When the clutch 28 is operated as just described, the slide valve 263 in the intercepting valve device 26I will maintain closed the communication'between pipe 59 and chamber 58 in motor 54, so that there can be no waste of fluid under pressure by releasing and subsequently supplying fluid under pressure to chamber .58, as hereinafter described.

If, when clutch 23 is disengaged, the operator actuates lever 68 to engage and subsequently disengage clutch 24, the intercepting valve device 26I will operate to automatically disconnect pis ton chamber'56 from pipe 51 when the piston 55 attains its clutch fully engaged position in order to relieve said chamber of pressure of fluid to thus relievethe parts of clutch 24 of actuating force, and also to prevent waste of fluid under pressure by flow to chamber 56 in case the operator, after releasing fluid under pressure from pipe 51, should subsequently operate lever 68 to resupplyfluid underpressure to said pipe. Further, with clutch 23' disengaged and piston chamber 49 disconnected from pipe 58, a waste of fluid under pressure can not occur by flow to said chamber upon supply of fluid under pressure to pipe 59 to effect disengagement of clutch 24, as will be evident from the above description.

Generdiremark Figs. 1 to 9 From the above description it will be noted that when either clutch 23 or 24 is fully engaged, the operator, by-mov-inglever 68 to, respectively, position I39 or position l4I, may at the same time effect full engagement of the other clutch, but it isnot intended that the operator will ever cause full engagement ofboth clutches at the same time. It will thus be seen that it is left to the judgment of the operator to limit the degree of engagement of one clutch to less than full engagement when the other clutch is fully engaged, andoperators are fully capable of so controlling the apparatus. -If desired however, the engagement of both clutches 23 and 24 at the same time can be prevented by a structure such as shown in Fig. 10 of the drawinga'or when one clutch is fully engaged the-engagement of the other can be limited to a degreeless than full engagement by either one of the structures shown in Figs. 11, l3,orl4.

Description Fig. 10

According to this modification the clutch disengaging pipe 58 is disconnected from chambers 49 and 58 in the two respective clutch control motors 45 and 59 and connected to one end of two double check valve devices I85 and I86. The side outlet of the double, check valve device I85 is connected by a pipe I81 to piston chamber 49 in the clutch control motor 45, while the side outlet of the double check valve device I86 is connected by a pipe I88 to piston chamber 58 in the clutch control motor 54. The opposite end outlets of the double check valve devices I85 and I86 are connected to pipes I89 and I99 respectively. The pipes I89 and I99 lead to two interlock valve devices I9I and I92 which are arranged for control by pistons46 and,55 in the clutch control motors 45 and 54 respectively. 4, g

The two double check valve devices I85 and I86 are identical instructure and operation, each comprisinga double check valve I93, shown only in the device I85, for controlling communication between the three pipes connected to the device. In the double check valve device I85 the double check valve I93 is operative upon supply of fluid under pressure to pipe 59, when fluid under pressure is released from pipe I89, to open communication between pipe 58 and pipe I61 and to close communication between pipe I81 and I99, while upon supply of fluid to pipe I89 when fluid under pressure is released from pipe 59, the double check valve I93 is'operative to close communicationbetween pipe lfift and pipe 58, and to open pipe I81 to pipe I89. The double check valve device I86 is operative in the same manner as the double check valve device I85. to control communication between ipes 59, I88 and I99.

The interlock valve devices-HI and I92 may be identical and of any conventional structure, each comprising for the purpose of illustration, "a cas i-ng I94 having a bore in whihthere is steamy mounted a piston like va1ve195. the interlock slide valve device "I91, the slide valve 195 isconnected by a link I96 to the clutch controllever 329 at its connection to piston "56 in "the clutch con-- trol'motor 45, while in the interlock valve device 1"92, the slide valve 195 similar-1y "connected to piston 55 in'the clutch control motor 52. "Each of the slide valves l95has a cavity F9! which, with the piston-46 or 55 in the disengaged position shown in the drawings, connects-pipe I89 or I90 to a relativelyrestricted passage "I98 which 'isiopento atmosphere. When the clutch control piston 46 or '55 moves toits'outerposition for effooting engagement "of therespective clutch the slide valve I95 in the respective interlock valve device I9I or I92 is loperated'tobreak communi cation between pipe I89 or pipe I90 and the respective atmospheric passage I 98 andto connect said pipe to pipe I99 or pipe 299 respectively. Pipes I99 and 200 lead respectivelyto'pipesi5l and.

In operation, let it be assumed that lever '68 has been operated to supply fluid under pressure to pipe 51 and thence to chamber .56 in the clutch control motor'4 to (effect engagement of clutch 2'4, and that said lever has also been depres -ed to'below the line I for causing operation of the engine at or above idling speed, under which condition pipe will be open to atmosphere, as well .95 pipe 'I 81 and I88 by way of pipe5i or reasons which will be evident from the following description. With piston iinthe clutch control motor .54 in its lower position eifecting full engagement of clutch 24 it will be noted that slide valve I in the interlock valve .device I92 will beso positioned as 'tobreak'communication Lbetween pipe 1.90 andthe atmospheric exhaust port I98 and to connect said pipe by way of cavity I91 to pipeilm leading to pipe '58.

Now let it .be assumed that with c1utch2 'l "fully engaged and with the control lever '68 depressed .to or below the line I16 the operator actuates said lever to efiect a supplyof fluid under pr ssure to pipe 48 to cause engagement of clutch 23. This operation of lever 68 will also actuate the selector valve device 12 to release ii'uid under pressure from pipe .51 and thereby from chamber .55 in the clutchcontrol motor '54,' ]out this will have no effect upon clutch vM .in its .fullyenga'ged position.

Fluid under pressure supplied to pipe 49 to efiect engagement of clutch .23 as just' described will flow from said pipe through pipe 1291!, cavity "It' WiII thus be seen that with the omen 1 1 fully engaged the operator cannot engage clutch '23 without effecting disengagement offclutch vM. therefore both clutches cannot t the same time be engaged.

'When piston 55 in the clutch-control motor 54 moves from its clutch engaging position to its *upperor disengaging positionto effect diseneagerness-er clutch 124. it-will shift the slide valve in the interlock valve device 4-92 trom the position connecting pipes 200 and 1:99 to the position in which this communication is closed and pipe I Sill is open "to atmosp-here through the restricted exhaust port I98. The port 198 is restricted as just mentioned so as to retain a sumcient pressure of fluid in chamber 58 after :cutting off thesupply-of fluid pressure thereto trom pipe 2 119 to insure -f-ull move'ment 'o'f piston 55 to its clutch disengaging position, lollo'vv ing which said pressure -gradual-ly will be dissipated to the atmosphere, so that the clutch control motor 55 will be in condition to operate in case the operator subsequently supplies flu d under pressure to pipe 5='I for effecting engagement of clutch 24.

(If clutch '23 is fully engaged and the operator actuates lever 68 "to effect engagement of clutch 24,"the'structurewil1 operate to elfect disengagemerit of clutch 23 in a manner which will be obvious from the above description, in order to prevent both clutches being engaged at the same time.

Description Fig .11

According to this modification I associatewith the clutch control motor '45 an interlock valve device 263 Parrangedffor operation by piston 4B in said imotor through thexmedium .of a connecting link 2% to control communication between pipe 5?! and a pipe 265 leading to schamber 56 ":il'l the clutch :control motor 54. A like interlock valve device 296 is associated with the clutch control motor 55 'for adjustment by piston 5.5 therein through the medium of a connecting Blink 203 to control communication between lpr pe 48 iand :a pipe 208 leading to piston chamber ii in the clutch =control motor 45.

"-I he interlock valve device ass comprises, for the purpose of illustration, a rotary plug "valve 299 wh ch is connected by a lever 2 l e to the link 2134, whereby said plug valve will be moved to two different positions corresponding to the disengaged and fully engaged positions of piston '45 in the motor '45. The plug valve 259 has a passageway ZI-I which with the piston 46 in its clutch disengaging pos tion, in which it is shown in the drawings, establishes communication between pipe 51 and pipe 2&5. When the piston 46 is moved to its clutch engaging position upon supply of fluid under pressure to chamber 41 the plug valve 209 will be moved to a posit on "to close communication between pipe 51 and pipe 295. Pipe 5 however, "is constantly open through passageway 2 in valve 299 to a pipe 2I2 which connected through a pressure limiting valve device 2| 3 to pipe 205.

'The interlock valve dev ce 295 is arranged to control communication between pipes 48 and 208 and a third pipe 2M in the same manner as the interlock valve device 203 controls communication between the pipes connected thereto. Thus with piston 55 in the fluid motor 54 in its clutch disengaging position, in which it is shown in thedrawings, pipe 43 will be open to pipe 208, while in the clutch engaging position of said piston this communication will be closedbut pipe 48 will remain connected to pipe 214. Pipe '2I4 is connected through a pressure limitingvalve device 2 I5 topi'pe 2E8.

The pressure lim ting valve devices create 245 may be of any suitable type adapted to limit the'pressure of fi-uid delivered thereby to a chosen 75 degree below the pressure of fluid supplied there to. In the present instance these limiting valve devices are adapted to limit the pressure of fluid at their outlets i. e., to pipes 205 and 208, for supply to chambers 41 and 55 in the fluid clutch control motors to such a degree as to prevent operation of piston 46 or 55 to effect full engagement of the respective clutch 23 or 24.

The pressure limiting valve devices 2l3 and H5 may be constructed as shown in Fig. 12, and therefore comprises a casing containing a flexible diaphragm 2|6 having at one side a chamber 2H which is open through a port 2H) and a passage 2I9 to an outlet pipe which may be either pipe 205 or 208 shown in Fig. 11. The casing has a chamber 220 adapted to be constantly open to either pipe 2l2 or 2M and containing a valve 22! arranged to control flow of fluid under pressure from said chamber to a chamber 222 which is open to the outlet pipe through passage 2|9. A spring 223 in chamber 220 acts on the valve 22I for urging it to a closed position. The valve 22! has a fluted stem 224 extending into chamber 2|! where it engages one side of the diaphragm 2l6. Bearng against the opposite side of diaphragm 2 I6 is one end of a coil spring 225. The opposite end of spring 225 engages an adjusting nut 225 having screw-threaded engagement with the casing whereby the pressure of said spring on the diaphragm 2H5 may be regulated.

The operation of the limiting valve device 2I3 and 2l5 is as follows:

When fluid under pressure is supplied to pipe 2 l2 or pipe 2l4 and thence to chamber 226 in the respective pressure limiting valve device H3 or 2 I 5, said pressure will equalize past the normally open valve 22I into chamber 222 and thence through passage 2H9 into chamber 2|! below the diaphragm, and also into the outlet pipe, which may be either pipe 205 or p'pe 208. When the pressure of fluid thus obtained in the outlet pipe and acting in chamber 21'! below diaphragm H6 is increased to a degree sumcient to overcome the opposing adjusted force of spring 225 the diaphragm will deflect against the opposing force of sa d spring and permit closing of valve 22! by spring 223 for thereby limiting the pressure in passage '2 l8 and in the outlet pipe to a degree predetermined by the adjusted force of spring 225.

The operation of the apparatus shown in Fig. 11 is as follows:

Let it be initially assumed that both of the clutches 23 and 22 ac disengaged and pistons 46 and 55 in the clutch control motors 45 and 54, respectively, are in their disengaged position, as shown in the drawing. Now let it be assumed that the operator actuates the control lever 68 to efiect a supply of fluid under pressure to -pipe 51 for causing engagement of clutch 24. The fluid pressure thus supplied to pipe 5'! will flow through passare 2 il in the interlock valve device 203 to pipe 255 and thence to piston chamber 55 in the clutch motor 54. The piston 55 in this motor will then operate to effect engagement of clutch 24, as will be apparent from preceding description. With clutch 24 thus fully engaged the interlock valve device 265 will be operated to close communication between pipe 48 and pipe 268 while maintaining open the communication between pipe 48 and pipe 214.

With clutch 24 thus fully engaged let it now be assumed that the operator desires to also engage clutch 23- in order to obtain a desired Jerk on the lifting cable 2. To accomplish this he will move his lever 58 as required to supply fluid under pressure to pipe 48. Fluid thus supplied to pipe 48 will then flow through the interlock valve device 266 to pipe 2! and thence through the limiting valve device 2l5 to pipe 253 leading to chamber 41 below the piston 45 in the clutch control motor 45. The piston 45 will then operate to effect engagement of clutch 23 to a partial degree as limited by the reduced pressure of fluid attained in pipe 258 through the limiting valve device 215. Thus while clutch 24 is fully engaged the clutch 23 may also be engaged but the limiting valve device 2l5 will limit the degree of engagement of the latter clutch to less than full engagement.

If clutch 23 is fully engaged, the clutch 24 may also be engaged but only to a partial degree on account of the pressure limiting action of the limiting valve device 2 l3 as will be clear from the above description.

Description Fig. 13

According to this modification of the invention I associate with each of the clutches or clutch motors means operable upon full engagement of either one of the clutches to limit the degree of movement of the clutch engaging lever 39 or 5| for the other clutch to less than required to eflect full engagement of said other clutch.

To illustrate this embodiment I provide an extension 22'! on lever 39, and by lines 228 and 229 I have indicated the positions which said lever extension will occupy with clutch 23 fully engaged and engaged to the chosen maximum partial degree, respectively.

A pneumatic blocking device 235 is associated with the casing of the clutch control motor 45. The device 239 comprises a casing containing a piston 23l and a rod 232 arranged to be moved by said piston into the path of movement of extension 22'! of the clutch control lever 39 to prevent movement of said lever past the partially engaged position indicated by the line 229. At one side of piston 23! is a pressure chamber 233 for receiving fluid under pressure to actuate said piston to move rod 232 into the path of movement of extension 221 for the purpose just described, while at the opposite side of said piston is a non-pressure chamber 234 containing a spring 235 which is operative when fluid is released from chamber 233 to actuate said piston to move rod 232 out of the path of movement of the extension 221 of the clutch control lever 39. The pressure chamber 233 is connected by a pipe 236 to an interlock valve device 231 to which is also connected a pipe 238 arranged to receive fluid under pressure from any suitable source of fluid under pressure such as pipe 55 as Will be later brought out.

The interlock valve device 23? may comprise a casing containing a plug valve 239 arranged to be turned to two different positions by a lever 240 connected by a link 2 5i to the clutch control lever 5! for operation by the piston in the clutch control motor '54. The plug valve 239 has a passage 242 which, with the motor 54 in the condition fully engaging clutch 24, establishes communication between pipes 236 and 238, while upon disengagement of said clutch by operation of said motor the plug valve will be turned by lever 240 and link 24! to a position in which this communication is closed.

Associated-with motor 52 is a pneumatic blocking device 243 which is identical to and which is arranged to cooperate with an extension 244 of the clutch control lever 5lin the same manner as the blocking device 230 cooperates with extension 22! of lever 39, as above described. The

he. nd of the exten i n" lo in s l alq 25.4 t difi l 9r i qk the; meme e 2 in la chum l b sw 'e. direet on, as'vi wd Fig- 1 t9 .a' in n whi h .a'fill iw 55 pyovided on the qppos te rend 9f sgidipembelf is 1;; the p th. o mofi n m o th e ten 4 1 o the cluteh v cgntr ql leizep 5,1 50 as to thereby limit its de ee o mo em nt Of the lat eli by th ete 5 $01 s re u red to fi i 1 1 engagen mntof clutch 2 The position whigp ,mempeg 259 will gss pme upon operation of fluid motor 55 to effect full engagement of clute kl" 2%, and t e manner i wh ch sai m mb r l mit til, degree of operation f the motor 54 agd tl gerejqy he e ree of en a em n ut h UQQ Z thi vqotn tic rt ar il etmte .Fi 5 f t e raw-- 111g.

T e em er .5.20 at the end 1Q:-29 te me m v d wit len ng eu fiaqe v2.54 a :rWefi lHllran ed m s .1 ce @515 awrtm er QQnteQ b t e ext sion 2, 3 9 the dumb-6911 2179 xer 59 up n ne tiqn 9 ms t r 541W e ect en a e- .ment .Q c ut h 2 for roc in he m mber 259. a. :al qkmise d recti n to t aere y m ve a 23mm 257 Q the .appqsi e en of: said member mm the path f moyem n Qf qx ension 734:8 f the c utch lever 39 tor limit n -operation .of t e la t nam d lever by mot r 4.5 t a degree less than requine to obtain 'full engagement of clutch' 23, Thus with clutch 24 fully engaged the clutch 25 can beengaged only to a partial degree,

From the above degcri ptio n it will-now be geen that the improt edbntrol eppgat ue provider; fO'r Selective cor'iti'bl' dftwq'clptc'hes' and if the Speed of an engine in suqh a manna? that the'engine ma be acc r te? e h r re r ef re m n p 2h? t ntc 'e rd r pro e gemt 'fth c 'utchee-ae ma bed si e i ce the qinti' o i e s cQhtm led' Mme??- Aecgrdin to this modification :there is pro- :vided "mechanicalfbloeking means, in pontrast' to the pneumatis bl ckine deviges ,shown 1p Eig. :13 and above dcsmhe chi epv aratiye u s 1111 e a ementot ei v e. clutch to. :hmitthe degree p g zlga emeat I m n w; it: l4 A e eepe e o i o 27 means, clutch control means operable to effect the engagement of said clutch, a control member *rotatable for effecting the operation of one of said control means, another control member movable longitudinally of the rotatable member for eflecting the operation of the other of said control means, and an actuating control element carried by the rotatable control member and operable to impart rotary movement to said rotatable control member and longitudinal movement to said other control member either individually or in unison.

2. In combination, two control pipes, two individual valve means one for controlling pressure of fluid in one of said pipes and the other for controlling pressure of fluid in the other of said pipes, said one valve means comprising fluid pressure controlling structure and a displaceable element for controlling said structure, said element having a normal position and being operable therein to efiect operation of said structure to Open the respective pipe to atmosphere, said element being adjustable out of said normal position to effect operation of said structure to supply fluid to the respective pipe at a pressure corresponding to the extent of such adjustment, said other valve means also comprising fluid pressure controlling structure and a displaceable element or in a second direction or in a third direction,

a first mechanism controlled by said lever for controlling the first named displaceable element and operative with said lever in its normal position to eflect movement of said first displace- -able element to its normal position and operable 1 upon movement of 'said lever out of its normal position in said one direction to effect movement of said first displaceable element out of its normal position to an extent corresponding to the "extent of movement of said lever, a second mechanism controlled by said lever for controlling the second named displaceable element and operative with said lever in its normal position to effect movement of said second displaceable element to its normal position and operable upon movement of said lever out of its normal position in said second direction to efiect movement of said second displaceable element out of its normal position, said lever being operable upon mo ement out of its normal position in said third direction to effect operation of said first mechaniim and Y of said second mechanism simultaneously to simultaneously displace the respective displaceable elements from their normal positions.

3. A control apparatus for controlling selectively the supply and release of .fluid under pressure to and from each of three control pipes comprising in combination, individual valve means for controlling the supply and release of fluid under a pressure to and from each of said pipes, an operators control lever, structure carrying said lever providing for movement of said lever out of its normal position in either one direction, a second direction Or in a third direction, a first mechanism controlled by said lever for control-" ling one of said valve means and operable with said lever in said normal position and upon movement of said lever in said second direction to effect operation of said one valve means to open the respective pipe to atmosphere and operable upon movement of saidlever out of said normal position in said one direction to eflect operation of said one valve means to supply fluid under pressure to the respective pipe, a second mechanism controlled by said lever for controlling a second one of said valve means and operable with said lever in its normal position and upon movement thereof in said one direction to effect operation of said second valve means to open the respective pipe to atmosphere and operable upon movement of said lever out of its normal position in said second direction to effect operation of said second valve means to supply fluid under pressure to said second pipe, said lever being operable upon movement out of said normal position in said third direction to efiect simultaneous operation of said first mechanism and of said second mechanism and thereby of said first valve means and of said second valve means to supply fluid under pressure to said first and second pipes simultaneously, said third valve means being controlled by pressure of fluid in said second pipe and being operable by pressure of fluid supplied thereto to release fluid under pressure from said third pipe and being operable upon release of fluid under pressure Irom said second pipe to supply fluid under pressure to said third pipe.

4. A control apparatus for controlling the supply and release of fluid under pressure to and from five control pipes comprising a first valve means operable to control the "supply and reltroiled by pressure of fluid in said third pipe and operable when the pressure in said third pipe exceeds a chosen degree to open said other two pipes to atmosphere and when less than said chosen degree to supply fluid under pressure to said other two-pipes, an operator's control lever, structure carrying said lever providing for movement of said lever in a horizontal plane in either one direction or in the opposite direction from a neutral position and also providing for. movement of said lever out of said horizontal plane in a vertical direction, mechanism controlled by said lever and operable upon movement thereof in said one direction to efiect operation of said one valve means to effect a supply of fluid under pressure to said one pipe and operable upon movement of said lever in said opposite direction to eflect operation of said second valve means to efiect a supply of fluid *under pressure to said second pipe, said second and one valve means comprising means oper- .ing a top wall, a shaft extending through and carried by and journaled in said wall, said shaft having an axial bore, a plunger slidable mounted in said bore, a pin arranged transversely of and carried by the end of said shaftextending above said wall, an operators control lever j ournaled on said pin, said lever being operab-ieupon movement in a direction circumferentially of said shaft to operate said pin ,to turn said shaft, said lever being also rockable on said pin in a direction longitudinally of said shaft, cam

means associated with said lever and operable upon rocking of said lever on said pin to displace said plunger in and relative to said shaft,

a structure in said housing controlled by displacement of said plunger, another structure in said housing, and cam means on said shaft withinsaid housing operable wpon rotation of said shaft to control said other structure.

6. -A control apparatus comprising in combination, two fluid motors peach comprising ,a casing, a movable power member in said casing subject on one side to pressure or fluid in a first chamber and subject on the opposite side to pressure of fluid in a second chamber and being movable to one position upon supply of fluid under pressure to said first chamber when fluid is released from said second chamber and being provable to a second position upon supply of fluid under pressure to said second chamber when fluid under pressure is releasedfrom said first chamber, a first control pipe arrangedto convey fluid under pressure to said first chamber in one of said motors, a second control pipe arranged to convey fluid under pressure to said first chamber in the other motor, a third control pipe arranged to convey fluid-under pressure to said second chamber in both of said motors simutaneously, control means selectively operable to supply fluid under pressure to either said first pipe and at the same time open said second and third pilpesto atmosphere, or to said second pipe and at the same time open said first and third pipes to atmosphere, said control means being also operable to open said first and second pipes to atmosphere and at the same time to supply fluid under pressure to saidthird pipe, and valve means arranged to be operated by fluid under pressure effective in said first chamber in either one of said motors to close communication'between said secend-chamber in the other motor and said third pipe and to supply fluid underpressure-to-the last named chamber.

'7. A control apparatus comprising in combination, two fluid motors each comprising a casing,

a movable power member in said'casing subject ,on ones ide to pressure of fluid in. a first chamber members out of its normal position to limit the .GXtent of movement of the other member out of and subject on the opposite side to pressure of g "thereof, and interlock mechanism 30 pressure is released from said first chamber, a first control pipe arranged to convey fluid under pressure to said first chamber in one of said motors, a second control pipe arranged toconvey fluid under pressure to said first chamber inthe other motor, a third control pipe arranged to convey fluid under pressure to said second chamber in both of said motors simultaneously,,con.- =trol means selectively operable to supply fluid under pressure to either said first pipe .and at the same time open said second and third-pipes to atmosphere, or to said second pipe and at-the same time open said first and third pipes .to atmosphere, said control means being also operable to open said first andsecond pipes to atmosphere and at the same time to supply fluid-under pressure to said third pipe, a first valve means arranged to be operated by fluid under pressure from said first pipe to disconnect said vsecond chamber in said second motor'frorn said :third pipe and to open the last named chamber to said first pipe, a second valve means arranged-to;he operated by fluid under pressure from saidsecond pipe-t0 disconnect said second chamber in .said first motor'from said third pipe and to open the last named chamber to said second pipe, valve structure controlled by said power member in said second motor controlling communication between said first pipe and firstvalve meansand arranged to cEose said communication with said power member in said first motor in said one position and to open said communication insaid second position, and. other valve structure controlled by saidpower member in said first motor controlling communication between said second pipe and said second valve means and arranged to close the last named communication with the power member in said first motor in its one posi tion andto open the last named communication with the power member in said first motor in its secondposition.

8. An apparatus for selectively controlling op.- eration of either one of two devices to effect either one or another of two difierent operations comprising in combination, a first motor arranged to control one of said devices, a second motor arranged to control the other of said devices, operators controlrneans comprising a lever and mechanism selectively responsive to different operations of said lever to effect operation of either one of said motors and thereby of the respective device to efiect said one operation operable by each motor uponoperation thereof to efiect said one operation of the-respective device, to effect operation of the'other motor and of the respective device to effect said other operation.

-9. In combination, twoseparate movable mem- -bers each having a normal position and a certain degree of movement out of said normal position,

two motors, one for each of said members, and each motor being operable to move the respective members to its normal position and out of its normal position, mechanism controlled by and rendered effective upon movement of one of said its normal position to a degree less than said certai degr s i m n m being ende e ineffective with said one member in its normal position, and operators control means selectively operable to efiect operation of either one of said motors to move the respective member either to or out of its normal position, or to efiect operation of both of said motors in sequence to effect escapee- 31 fndvement of first one and then the other of said members out of its normal positions.

10. In combination, two separate movable members each having a normal position and a certain degree of movement out of said normal position, two motors, one for each of said members, and each motor being operable to move the respective member to its normal position or out of its normal position a movable element movable into the path of movement of one of said members for engagement by the last named member in a position adapted to limit the extent of movement of said last named member out of normal position to a degree less than said certain degree, means operable, upon operation of the motor for the other member to eflfect movement or said other member out of its normal position, to efiect movement of said element into the path of movement of said one member, means operable to shift said element out of the path of movement of said one member upon operation of the last named motor to effect adjustment of said other member to its normal position, and control means operable to selectively efiect operation of either one of said motors to move the respective member out of and back to its normal position or to eiiect in sequence, operation first of said other motor and then of the motor for said one member to 'move the respective members out of their normal position.

11. In combination, two separate control members each having a normal position and a certain degree of movement out of said normal position, two fluid motors, one for each of said members, and each motor being operable upon supply of fluid under pressure thereto to adjust the respective member out of said normal position, a device associated with one of said motors and operable by fluid under pressure to limit the movement of the said member controlled by said one motor but of said normal position to an extent less than said certain degree, means operable to render said device ineflective upon release of fluid under pressure therefrom, and valve means'operably by the other motor with the respective member out of its normal position to establish a communication for supplying fluid under pressure to said device, and with the respective member in its normal position to release fluid under pressure from said device.

12. In combination, two separate control members each having a normal position and a certain degree of adjustment out of said normal position,

two fluid motors, one for each of said members,

and each motor being operable upon supply of fluid thereto to adjust the respective member out of its normal position to an extent corresponding to the pressure of such fluid, and to a maximum extent upon supply of fluid at a certain maximum pressure to the motor, operators control means selectively operable to supply fluid under pressure to either one of said motors, pressure limiting means associated with one of said motors operable to limit pressure of fluid supplied thereto by said control means to a degree less than said maximum pressure, and mechanism operable by the other motor upon movement thereof by fluid under pressure supplied by said operator's control means to render said pressure limiting means effective, and operable by said other motor with the "32 respective control member in norma1 position to render said pressure limiting means ineffective.

13. In combination, two clutches, two clutch control devices, one for each of said clutches, and each being Operable by disengaging force to disengage the respective clutch, and also operable by engaging force to engage th respective clutch to a degree dependent upon the degree of such force, an operator's control device selectively operable to provide anydesired degree, up to a maximum degree, of engaging force on either one of said control devices or on both of said control devices in sequence, and mechanism conditionable by one of said clutch control devices, when operated by clutch engaging force, to limit the degree of engaging force providable on the other clutch control device to adegree less than said maximum, said mechanism being rendered ineflective by the respective clutch control device when operated by clutch disengaging force.

14. In combination, two separate control members each having a certain range of adjustment from a normal position, two fluid motors, one for adjusting each of said members, first and second control pipes connected to each motor, each motor being operable upon supply of fluid to the respective first pipe when fluid under pressure released from the respective second pipe, to adjust the respective member out of normal position to a degree corresponding to the pressure of fluid in said respective first pipe, and each motor being operable upon release of fluid under pressure from the respectiv first pipe and supply of fluid under pressure to the respective second pipe to adjust the respective member to its normal position, controlmeans operable to selectively supply fluid under pressure to either one of the two first pipes and at the same tim to release fluid under pres-.

sure from the other first pipe and from both of the second pipes, and also operable to release fluid under pressure from both of said first pipes and at the same time to suppl fluid under pressure to both of said second pipes, and mechanism associated with each motor and rendered effective with the respective motor operated in response to pressure of fluid supplied to the respective first pipe to limit operation of the other motor to ad- 'justthe respective member to an extentless than its full range upon supply of fluid under pressure to the respective first pipe.

ROY R. STEVENS.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES Ser. No. 400,817, Mayba-ck (A. P. C.) published May 18, 1943. 

